FROM FARMERS TO COWBELLS: THE POSSIBILITY OF LOWER MISSISSIPPIAN GLACIO-EUSTATIC SIGNALS RECORDED IN THE VANCEBURG SEQUENCE (BORDEN FORMATION) OF KENTUCKY AND INDIANA

Recently, glacial studies and event stratigraphy have become more integrated. Stable isotopes, primarily d¹³C and d¹⁸O can be used to indicate several types of ancient events. Flucuations in carbon isotopes are proxy indicators for rates of organic matter burial and paleo-atmospheric conditions. Positive shifts in d¹³C are characteristic of cooler climates, resulting from an increase in the burial of organic matter. A positive shift in the d¹⁸O also indicates a cooling period. Saltzman et al. (2000) present data resulting in a positive d¹³C excursion in the upper Kinderhook (middle Tournaisian). Mii et al. (1999) present evidence of positive d¹³C and d¹⁸O excursions in the upper Kinderhook. Both Saltzman et al. (2000) and Mii et al. (1999) suggest the Lower Carboniferous (middle Tournaisian) experienced a cooling period. Successions in Gondwana, primarily in basins in Bolivia and Brazil, have Lower Tournaisian successions that contain glacial tillites and diamictites. Based on the stable isotope evidence and lithologic characteristics, we suggest a glacio-eustatic model for the sea-level drop near the end of the Kinderhook. This regression can be observed in the Lower Mississippian strata of northeastern Kentucky and Indiana. The Henley Bed is believed to have recorded the initial glacio-eustatic drop, and is the basal unit of the Vanceburg Sequence. The other parasequence sets within the Vanceburg Sewquence in Kentucky and Indiana also record the initial regression and the subsequent transgression near the Tournaisian – Visean (Osagean) boundary.